The present invention relates to an at least two shaft reactor/mixer, in particular for process engineering treatment—e.g. for devolatilization (degassing)—of highly viscose and/or solid-containing reaction substance and mixture as well as to a system including an end cap for a reactor/mixer and a discharge screw connector block being connectable with an end cap. This kind or reactors/mixers are applied for example in the production and processing of polymers and/or plastic materials as well as rubber and/or elastomers, i.e. in cases in which a good mixing effect and, if applicable, also a quick regeneration of free surfaces for the purpose of evaporating, respectively, devolatilization (degassing) shall be ensured. Further, such reactors/mixers should comprise a self-cleaning potential as good as possible, in order that as little as possible encrustation occurs at the reactor walls, respectively at the mixing instruments. This may namely lead to disturbing side reactions in the reactor chamber and therefore to contamination and inhomogeneity of the respective product to be produced.
A self-cleaning reactor/mixer is known from EP 0 715 882 A2. This reactor/mixer consists of two or more parallel shafts, which rotate in the same direction on which axially offset discs are arranged which comprise a not necessarily circular circumference. The discs comprise scrapers being distributed on their circumference.
The reactor/mixer is enclosed by a housing. The reactor/mixer shall be constructed in such a way that all surfaces of the scrapers may be cleaned kinematically and that all surfaces of the scrapers of a shaft being directed outwardly are convex in an arbitrary radial section through the mixer and are cleaned by an adjacent shaft or its scrapers or by the housing. Further, all inwardly directed surfaces of the scrapers of a shaft are concave in an arbitrary radial section through the mixer and are cleaned by the scrapers of an adjacent shaft. During the cleaning of the housing through the scrapers between the housing wall and the cleaning surface of the scraper, only angles greater than 90° occur at the product side. Further, during the mutual cleaning of the scrapers, only angles greater than 60°, preferably greater than 90°, occur among one another between the cleaned and the cleaning surface of the scrapers which contact one another.